Last week, the electronic payments company announced a new service for developers that will let software-writers accept credit card payments using PayPal without requiring buyers to have a PayPal account.
via PayPal to take your credit card, no account needed | The Download Blog – Download.com.
As long as Paypal will cover the chargebacks, I see it as a positive for the sellers and a chance for Paypal to increase their Paypal to Paypal transfers if a percentage of Guest Payments later convert to Paypal accounts.